// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008 Benoit Jacob <jacob.benoit.1@gmail.com>
// Copyright (C) 2015 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#define TEST_ENABLE_TEMPORARY_TRACKING
#define EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD 8
// ^^ see bug 1449

#include "main.h"

template<typename MatrixType>
void
matrixRedux(const MatrixType& m)
{
	typedef typename MatrixType::Scalar Scalar;
	typedef typename MatrixType::RealScalar RealScalar;

	Index rows = m.rows();
	Index cols = m.cols();

	MatrixType m1 = MatrixType::Random(rows, cols);

	// The entries of m1 are uniformly distributed in [0,1], so m1.prod() is very small. This may lead to test
	// failures if we underflow into denormals. Thus, we scale so that entries are close to 1.
	MatrixType m1_for_prod = MatrixType::Ones(rows, cols) + RealScalar(0.2) * m1;

	Matrix<Scalar, MatrixType::RowsAtCompileTime, MatrixType::RowsAtCompileTime> m2(rows, rows);
	m2.setRandom();

	VERIFY_IS_MUCH_SMALLER_THAN(MatrixType::Zero(rows, cols).sum(), Scalar(1));
	VERIFY_IS_APPROX(
		MatrixType::Ones(rows, cols).sum(),
		Scalar(float(
			rows *
			cols))); // the float() here to shut up excessive MSVC warning about int->complex conversion being lossy
	Scalar s(0), p(1), minc(numext::real(m1.coeff(0))), maxc(numext::real(m1.coeff(0)));
	for (int j = 0; j < cols; j++)
		for (int i = 0; i < rows; i++) {
			s += m1(i, j);
			p *= m1_for_prod(i, j);
			minc = (std::min)(numext::real(minc), numext::real(m1(i, j)));
			maxc = (std::max)(numext::real(maxc), numext::real(m1(i, j)));
		}
	const Scalar mean = s / Scalar(RealScalar(rows * cols));

	VERIFY_IS_APPROX(m1.sum(), s);
	VERIFY_IS_APPROX(m1.mean(), mean);
	VERIFY_IS_APPROX(m1_for_prod.prod(), p);
	VERIFY_IS_APPROX(m1.real().minCoeff(), numext::real(minc));
	VERIFY_IS_APPROX(m1.real().maxCoeff(), numext::real(maxc));

	// test that partial reduction works if nested expressions is forced to evaluate early
	VERIFY_IS_APPROX((m1.matrix() * m1.matrix().transpose()).cwiseProduct(m2.matrix()).rowwise().sum().sum(),
					 (m1.matrix() * m1.matrix().transpose()).eval().cwiseProduct(m2.matrix()).rowwise().sum().sum());

	// test slice vectorization assuming assign is ok
	Index r0 = internal::random<Index>(0, rows - 1);
	Index c0 = internal::random<Index>(0, cols - 1);
	Index r1 = internal::random<Index>(r0 + 1, rows) - r0;
	Index c1 = internal::random<Index>(c0 + 1, cols) - c0;
	VERIFY_IS_APPROX(m1.block(r0, c0, r1, c1).sum(), m1.block(r0, c0, r1, c1).eval().sum());
	VERIFY_IS_APPROX(m1.block(r0, c0, r1, c1).mean(), m1.block(r0, c0, r1, c1).eval().mean());
	VERIFY_IS_APPROX(m1_for_prod.block(r0, c0, r1, c1).prod(), m1_for_prod.block(r0, c0, r1, c1).eval().prod());
	VERIFY_IS_APPROX(m1.block(r0, c0, r1, c1).real().minCoeff(), m1.block(r0, c0, r1, c1).real().eval().minCoeff());
	VERIFY_IS_APPROX(m1.block(r0, c0, r1, c1).real().maxCoeff(), m1.block(r0, c0, r1, c1).real().eval().maxCoeff());

	// regression for bug 1090
	const int R1 = MatrixType::RowsAtCompileTime >= 2 ? MatrixType::RowsAtCompileTime / 2 : 6;
	const int C1 = MatrixType::ColsAtCompileTime >= 2 ? MatrixType::ColsAtCompileTime / 2 : 6;
	if (R1 <= rows - r0 && C1 <= cols - c0) {
		VERIFY_IS_APPROX((m1.template block<R1, C1>(r0, c0).sum()), m1.block(r0, c0, R1, C1).sum());
	}

	// test empty objects
	VERIFY_IS_APPROX(m1.block(r0, c0, 0, 0).sum(), Scalar(0));
	VERIFY_IS_APPROX(m1.block(r0, c0, 0, 0).prod(), Scalar(1));

	// test nesting complex expression
	VERIFY_EVALUATION_COUNT((m1.matrix() * m1.matrix().transpose()).sum(),
							(MatrixType::IsVectorAtCompileTime && MatrixType::SizeAtCompileTime != 1 ? 0 : 1));
	VERIFY_EVALUATION_COUNT(((m1.matrix() * m1.matrix().transpose()) + m2).sum(),
							(MatrixType::IsVectorAtCompileTime && MatrixType::SizeAtCompileTime != 1 ? 0 : 1));
}

template<typename VectorType>
void
vectorRedux(const VectorType& w)
{
	using std::abs;
	typedef typename VectorType::Scalar Scalar;
	typedef typename NumTraits<Scalar>::Real RealScalar;
	Index size = w.size();

	VectorType v = VectorType::Random(size);
	VectorType v_for_prod = VectorType::Ones(size) + Scalar(0.2) * v; // see comment above declaration of m1_for_prod

	for (int i = 1; i < size; i++) {
		Scalar s(0), p(1);
		RealScalar minc(numext::real(v.coeff(0))), maxc(numext::real(v.coeff(0)));
		for (int j = 0; j < i; j++) {
			s += v[j];
			p *= v_for_prod[j];
			minc = (std::min)(minc, numext::real(v[j]));
			maxc = (std::max)(maxc, numext::real(v[j]));
		}
		VERIFY_IS_MUCH_SMALLER_THAN(abs(s - v.head(i).sum()), Scalar(1));
		VERIFY_IS_APPROX(p, v_for_prod.head(i).prod());
		VERIFY_IS_APPROX(minc, v.real().head(i).minCoeff());
		VERIFY_IS_APPROX(maxc, v.real().head(i).maxCoeff());
	}

	for (int i = 0; i < size - 1; i++) {
		Scalar s(0), p(1);
		RealScalar minc(numext::real(v.coeff(i))), maxc(numext::real(v.coeff(i)));
		for (int j = i; j < size; j++) {
			s += v[j];
			p *= v_for_prod[j];
			minc = (std::min)(minc, numext::real(v[j]));
			maxc = (std::max)(maxc, numext::real(v[j]));
		}
		VERIFY_IS_MUCH_SMALLER_THAN(abs(s - v.tail(size - i).sum()), Scalar(1));
		VERIFY_IS_APPROX(p, v_for_prod.tail(size - i).prod());
		VERIFY_IS_APPROX(minc, v.real().tail(size - i).minCoeff());
		VERIFY_IS_APPROX(maxc, v.real().tail(size - i).maxCoeff());
	}

	for (int i = 0; i < size / 2; i++) {
		Scalar s(0), p(1);
		RealScalar minc(numext::real(v.coeff(i))), maxc(numext::real(v.coeff(i)));
		for (int j = i; j < size - i; j++) {
			s += v[j];
			p *= v_for_prod[j];
			minc = (std::min)(minc, numext::real(v[j]));
			maxc = (std::max)(maxc, numext::real(v[j]));
		}
		VERIFY_IS_MUCH_SMALLER_THAN(abs(s - v.segment(i, size - 2 * i).sum()), Scalar(1));
		VERIFY_IS_APPROX(p, v_for_prod.segment(i, size - 2 * i).prod());
		VERIFY_IS_APPROX(minc, v.real().segment(i, size - 2 * i).minCoeff());
		VERIFY_IS_APPROX(maxc, v.real().segment(i, size - 2 * i).maxCoeff());
	}

	// test empty objects
	VERIFY_IS_APPROX(v.head(0).sum(), Scalar(0));
	VERIFY_IS_APPROX(v.tail(0).prod(), Scalar(1));
	VERIFY_RAISES_ASSERT(v.head(0).mean());
	VERIFY_RAISES_ASSERT(v.head(0).minCoeff());
	VERIFY_RAISES_ASSERT(v.head(0).maxCoeff());
}

EIGEN_DECLARE_TEST(redux)
{
	// the max size cannot be too large, otherwise reduxion operations obviously generate large errors.
	int maxsize = (std::min)(100, EIGEN_TEST_MAX_SIZE);
	TEST_SET_BUT_UNUSED_VARIABLE(maxsize);
	for (int i = 0; i < g_repeat; i++) {
		CALL_SUBTEST_1(matrixRedux(Matrix<float, 1, 1>()));
		CALL_SUBTEST_1(matrixRedux(Array<float, 1, 1>()));
		CALL_SUBTEST_2(matrixRedux(Matrix2f()));
		CALL_SUBTEST_2(matrixRedux(Array2f()));
		CALL_SUBTEST_2(matrixRedux(Array22f()));
		CALL_SUBTEST_3(matrixRedux(Matrix4d()));
		CALL_SUBTEST_3(matrixRedux(Array4d()));
		CALL_SUBTEST_3(matrixRedux(Array44d()));
		CALL_SUBTEST_4(matrixRedux(MatrixXcf(internal::random<int>(1, maxsize), internal::random<int>(1, maxsize))));
		CALL_SUBTEST_4(matrixRedux(ArrayXXcf(internal::random<int>(1, maxsize), internal::random<int>(1, maxsize))));
		CALL_SUBTEST_5(matrixRedux(MatrixXd(internal::random<int>(1, maxsize), internal::random<int>(1, maxsize))));
		CALL_SUBTEST_5(matrixRedux(ArrayXXd(internal::random<int>(1, maxsize), internal::random<int>(1, maxsize))));
		CALL_SUBTEST_6(matrixRedux(MatrixXi(internal::random<int>(1, maxsize), internal::random<int>(1, maxsize))));
		CALL_SUBTEST_6(matrixRedux(ArrayXXi(internal::random<int>(1, maxsize), internal::random<int>(1, maxsize))));
	}
	for (int i = 0; i < g_repeat; i++) {
		CALL_SUBTEST_7(vectorRedux(Vector4f()));
		CALL_SUBTEST_7(vectorRedux(Array4f()));
		CALL_SUBTEST_5(vectorRedux(VectorXd(internal::random<int>(1, maxsize))));
		CALL_SUBTEST_5(vectorRedux(ArrayXd(internal::random<int>(1, maxsize))));
		CALL_SUBTEST_8(vectorRedux(VectorXf(internal::random<int>(1, maxsize))));
		CALL_SUBTEST_8(vectorRedux(ArrayXf(internal::random<int>(1, maxsize))));
	}
}
